Pocket-Book of Aeronautics, by Hermann W.L. Moedebeck in Collaboration with O. Chanute and Others

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 Excerpt: ... photograph. Now repeat the same process for the second photograph, keeping to the same horizontal plane. If the point r' of the second photograph is known to be identical with the point r of the first, and if R' is the point corresponding to r' in the horizontal plane, then R and R' will not in general coincide. If they happen to fall together, then the true point on the earth, projected from C and C to K and R' of the horizontal plane, coincides with them both, and lies in the point R (Rj in the horizontal plane. In the general case the point on the land must be graphically constructed or calculated as the point of intersection of the lines C R and 0' R'. The fact that these lines cut one another actually in space gives an excellent control of the whole foregoing construction. The construction of a map from balloon photographs, in addition to its especial use in war, may be advantageously employed to survey flat unapproachable land (such as marsh land). The views obtained from a balloon, especially taken from a captive balloon where the height is not very great, are frequently insufficient for the survey of very hilly land. LITERATURE. Photographic surveying in general: --Koppe, Photogrammetrie. Weimar, 1889. Koppe, Photogrammetrie und Wolkenmessung. Braunschweig, 1896. Finsterwalder, Die geometrischen Grundlagen der Photogrammetrie, Berichie des Deutsehen Math.-Vereins., vi. 2. Steiner, Die Photographie im Dienste des Ingenieurs. Vienna, 1891. Dolezal, ' Die Anwendung der Photographie in der praktischen Messkunst. Halle, 1896. Vol. xxii. of the Encyklopadie der Photographie. Photographic surveying from balloons: --Finsterwalder, Ortsbestimmung im Ballon, Illustrierte Aeron. Mitt., 1899. Finsterwalder, Cberdie Konstructio...